As digital content continues to proliferate, management of digital assets becomes an increasingly difficult challenge. Enhancements in computer networking and database technology allow companies to manage large collections of images and other media and make the content available to third parties. While network communication provides a powerful tool to enable the manager of the database to share content with others, it makes it more difficult to control and track how the content is being used.
For example, some companies maintain extensive databases of images and other media content used to promote their products. Customers or service providers such as advertising and marketing firms can access this content remotely via extranet, web site, or other file transfer transactions. Though computer networking telecommunication technology facilitates access, it makes it difficult to ensure that the customers and services providers are getting the latest content, and that they are getting accurate and helpful information relating to the content.
In these applications, there is a need to enable digital asset management to reliably link media content with additional data about the content. One way to associate content with information about the content is to place the information in a file header or footer. This approach, however, is less effective because the information often does not survive file format changes, conversion to the analog domain, etc. Another way to associate multimedia content with other data is to hide identifying information in the content through data hiding or steganography. Steganography refers to a process of hiding information into a signal. One example of steganography is digital watermarking. Digital watermarking is a process for modifying media content to embed a machine-readable code into the data content. The data may be modified such that the embedded code is imperceptible or nearly imperceptible to the user, yet may be detected through an automated detection process. Most commonly, digital watermarking is applied to media such as images, audio signals, and video signals. However, it may also be applied to other types of data, including documents (e.g., through line, word or character shifting), software, multi-dimensional graphics models, and surface textures of objects.
Digital watermarking systems have two primary components: an embedding component that embeds the watermark in the media content, and a reading component that detects and reads the embedded watermark. The embedding component embeds a watermark by altering data samples of the media content in the spatial, temporal or some other transform domain (e.g., Fourier, Discrete Cosine, Wavelet Transform domains). The reading component analyzes target content to detect whether a watermark is present. In applications where the watermark encodes information (e.g., a message), the reader extracts this information from the detected watermark.
The present assignee's work in steganography, data hiding and watermarking is reflected in U.S. Pat. No. 5,862,260; in copending application Ser. No. 09/503,881 (now U.S. Pat. No. 6,614,914) and Ser. No. 09/452,023 (now U.S. Pat. No. 6,408,082); and in published specifications WO 9953428 and WO0007356 (corresponding to U.S. Ser. No. 09/074,034 (now U.S. Pat. No. 6,449,377) and Ser. No. 09/127,502(now U.S. Pat. No. 6,345,104)). A great many other approaches are familiar to those skilled in the art. The artisan is presumed to be familiar with the full range of literature about steganography, data hiding and watermarking. The subject matter of the present application is related to that disclosed in U.S. Pat. Nos. 5,862,260, 6,122,403 and in co-pending applications Ser. Nos. 09/503,881 filed Feb. 14, 2000 (now U.S. Pat. No. 6,614,914), 60/198,857 filed Apr. 21, 2000, Ser. No. 09/571,422 filed May 15, 2000 (now U.S. Pat. No. 6,947,571), Ser. No. 09/620,019 filed Jul. 20, 2000, and Ser. No. 09/636,102 filed Aug. 10, 2000; which are hereby incorporated by reference.
The disclosure describes methods and systems for managing digital content using watermarks to link the content to related metadata. In one method, a watermark reader device reads a watermark embedded into media content. The watermark conveys watermark information, such as a content identifier and creator identifier. The reader forwards the watermark information to a router. The router then uses the watermark information to find a metadata database identifier. It then sends a request for metadata along with the watermark information to the metadata database identified by the metadata database identifier. The metadata database uses the watermark information to find related metadata for the media content and sends the related metadata to the reader device.
One aspect of the invention is a method for processing media content on a distributed network. The method comprises: identifying media content signals stored at sites distributed over the distributed computer network; extracting content identifiers from the content signals; using the content identifiers to obtain metadata used to classify the media content signals; and creating a searchable index of the media content signals based on the metadata, wherein users access the searchable index on the distributed computer network to submit a search query for the searchable index to retrieve links to the media content signals.
Another aspect of the invention is a method for searching for audio or images on a distributed computer network comprising: from a location in the distributed computer network, receiving a query for content signals related to a first content signal, the first content signal being part of the query; receiving a content identifier extracted from audio or image data of the first content signal; using the content identifier to obtain metadata used to classify the first content signal; searching a searchable index of media content signals based on the metadata, which forms search criteria for the first content signal; and returning a set of search results including references to content signals stored in the distributed computer network that correspond to the search criteria.
Further features will become apparent with reference to the following detailed description and accompanying drawings.